Natalism is an ideology that promotes the reproduction of human life as an important objective of being human and advocates high birthrate. According to the Merriam-Webster dictionary, the term, as it relates to the belief itself, dates from 1971 and comes from French: nataliste, formed from French: natalité, birthrate.

Birth rate, also known as natality, is the total number of live human births per 1,000 population for a given period divided by the length of the period in years. The number of live births is normally taken from a universal registration system for births; population counts from a census, and estimation through specialized demographic techniques. The birth rate is used to calculate population growth. The estimated average population may be taken as the mid-year population.